Configuring Inter-AS BGP VPLS in Option B Mode

The advantage of the inter-AS Option B mode is that ASBRs exchange information through routes rather than dedicated links. The disadvantage of the inter-AS Option B mode is that label mappings need to be configured on ASBRs, and consequently, a great number of labels are consumed. In addition, an ASBR needs to set up an LSP with each PE, which results in the shortage of label resources on the ASBR and easily leads to a bottleneck.

Procedure

Configure BGP VPLS on each PE and ASBR in each AS. For configuration details, see Configuring BGP VPLS.
Configure an MP-IBGP connection on each ASBR in each AS.
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  
  The BGP view is displayed.
3. Run peer ipv4-address as-number as-number
  
  An AS number is set for a specified peer.
4. Run peer { group-name | ipv4-address } connect-interface { interface-type interface-number | ipv4-source-address }
  
  A source interface from which BGP messages are sent or a source address used for initiating a connection is specified.
5. Run l2vpn-ad-family
  The L2VPN-AD address family view is displayed.
6. Run policy vpn-target
  The device is enabled to filter routes based on VPN targets.
7. Run tunnel-selector tunnel-selector-name
  A tunnel selector is specified.
8. Run signaling vpls
  The VPLS signaling capability is enabled.
9. Run peer ipv4-address enable
  The capability to exchange routes with a specified BGP peer is configured.
10. Run quit
  Return to the system view.
11. Run commit
  The configuration is committed.